CABG Graft Failure Outcomes in Women

Quick Takes

  • A current pooled analysis of individual patient data from randomized clinical trials with systematic imaging follow-up showed that at 1 year, women had higher rates of graft failure compared to men (37.3% vs. 32.9% at the patient level and 20.5% vs. 15.8% at the graft level; p = 0.02 and < 0.001, respectively).
  • Graft failure was a predictor of adverse outcomes in women (MI and repeat revascularization [OR, 3.94; 95% CI, 1.79-8.67] and death [OR, 3.18; 95% CI, 1.73-5.85]).
  • Though female sex was a predictor of death related to CABG, it was not specifically due to increased risk of graft failure.

Study Questions:

What is the incidence of coronary artery bypass surgery (CABG) graft failure in women, its association with cardiac events, and its contributions to sex-related differences in outcomes?

Methods:

A pooled analysis of individual patient data from randomized clinical trials (RCTs) with systematic imaging follow-up was performed. Multivariable logistic regression models were used to assess the association of graft failure with myocardial infarction (MI) and repeat revascularization between CABG and imaging (primary outcome) and death after imaging (secondary outcome). Mediation analysis was performed to evaluate the effect of graft failure on the association between female sex and risk of death.

Results:

Seven RCTs (4,413 patients, 777 women) were included. At a median imaging follow-up of 1.03 years, graft failure was significantly more frequent among women than men (37.3% vs. 32.9% at the patient-level and 20.5% vs. 15.8% at the graft level; p = 0.02 and < 0.001, respectively). In women, graft failure was associated with an increased risk of MI and repeat revascularization (odds ratio [OR], 3.94; 95% confidence interval [CI], 1.79-8.67) and death (OR, 3.18; 95% CI, 1.73-5.85). Female sex was independently associated with the risk of death (direct effect, hazard ratio [HR], 1.84; 95% CI, 1.35-2.50) but the association was not mediated by graft failure (indirect effect, HR, 1.04; 95% CI, 0.86-1.26).

Conclusions:

Graft failure is more frequent in women and is associated with adverse cardiac events. The excess mortality risk associated with female sex among CABG patients is not mediated by graft failure.

Perspective:

Prior data have shown that women undergoing surgical coronary revascularization have worst outcomes, including mortality compared to men. Reasons for these findings remain incompletely understood (baseline risk, surgical technique, and/or biology). A current pooled analysis of individual patient data from randomized clinical trials with systematic imaging follow-up showed that at 1 year, women had higher rates of graft failure compared to men (37.3% vs. 32.9% at the patient level and 20.5% vs. 15.8% at the graft level; p = 0.02 and < 0.001, respectively) and graft failure was a predictor of adverse outcomes in women (MI and repeat revascularization [OR, 3.94; 95% CI, 1.79-8.67] and death [OR, 3.18; 95% CI, 1.73-5.85]). Though female sex was a predictor of death related to CABG, it was not specifically due to increased risk of graft failure. There remains a need to address the higher incidence of graft failure in women and to better understand residual disparities in clinical outcomes among women undergoing CABG.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention

Keywords: Cardiac Surgical Procedures, Coronary Artery Bypass, Women


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